We have measured antibodies to gliadin (AGA), bovine beta-lactoglobulin, and chicken egg ovalbumin with a four-layer solid phase radioimmunoassay (RIA) in 62 children and adolescents with coeliac disease and in 36 healthy controls. The geometric mean titre of IgG AGA in patients at initial diagnosis was more than 100-fold that of controls (p less than 0.0001). Even patients on gluten-free diet had significantly higher IgG AGA titres than the controls (p = 0.0001), the difference being more than 5-fold. All the 42 patients with active disease (30 at initial diagnosis and 12 after gluten challenge) had their IgG AGA titre above 1,000, as compared with 2 (5.7%) of the 35 controls (p less than 0.0001). Both IgG and IgA AGA were quite sensitive and specific in identifying children with coeliac disease; the sensitivities for IgG and IgA AGA were 100% and 95.2%, the specificities 94.3% and 97.2%, respectively. We conclude that determination of IgG and IgA AGA with RIA is suitable for monitoring dietary compliance in children with coeliac disease, and the method is sensitive and specific for screening for coeliac disease in children.